Under-shingled article handling and stacking system and method

ABSTRACT

A device and process for processing flat articles such as pieces of paper by utilizing a stream of under-shingled flat articles and generating a gap at predetermined intervals. The under-shingling process incorporates an accelerating and decelerating portion wherein each flat article is accelerated and then decelerated while a tail portion of the article is lifted such that the next flat article can slide underneath to establish an under-shingled stream.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/074,318, filed Mar. 29, 2011, entitled “UNDER-SHINGLED ARTICLEHANDLING AND STACKING SYSTEM AND METHOD,” now U.S. Pat. No. 8,360,413,issued Jan. 29, 2013, which is a continuation of U.S. patent applicationSer. No. 12/330,417, filed Dec. 8, 2008, now U.S. Pat. No. 7,918,443issued on Apr. 5, 2011, entitled “UNDER-SHINGLED ARTICLE HANDLING ANDSTACKING SYSTEM AND METHOD,” which claims benefit of U.S. ProvisionalPatent Application No. 61/012,415, filed Dec. 7, 2007, entitled“UNDER-SHINGLED ARTICLE HANDLING AND STACKING SYSTEM AND METHOD,” thespecifications of which are incorporated herein in their entirety.

TECHNICAL FIELD

The present invention relates to a system and method for under-shinglinga flat or folded article in web printing systems, and in particularsystems for creating under-shingled streams of flat articles, systemsfor placing a gap in a continuous stream of under-shingled articlesand/or systems for stacking such under-shingled streams of articles intoreceptacles in a continuous and indexed manner. Embodiments of thisinvention are related to a system wherein a web of paper is utilized ina high speed printing or product manufacturing system where ink isapplied to the web, the web is cut into pieces and the pieces arehandled by various processes until they are turned into a stream offinished product.

BACKGROUND

Systems and apparatus that already exist in the industry that arecapable of handling flat articles may begin as a single printed web ofpaper that is cut. Each individual cut piece is handled such that itcreates an over-shingled stream of product. Referring to FIG. 1, thereis shown a prior art system wherein a web of printed material 10 entersthe finishing portion of the paper handling device. The web 10 is movingat a continuous speed. At predetermined times a cutter 12 cuts the webinto a product piece 16 having a predetermined size or length. There arevarious types of cutters in the market place and every manufacturer ofsuch cutters 12 have different ways of cutting pieces from a web. Ofcourse, once a piece is cut, for example, the piece 16 must be handledby the machinery. Generally, the leading edge 13 of a cut piece 16 isgrabbed by a gain device 14 which accelerates the cut piece 16 to aspeed slightly greater than the speed of the web 10. The accelerationplaces a spacing 15 or gap between the cut piece and the end 17 of theweb 10. The cut piece 16 is then sent in a somewhat free floatingfashion into a diverter 18 where the leading edge 13 of the cut piece 16comes in contact with a conveyor belt that runs slower than the nowapproaching piece of cut material 16. A diverter 18 (variousmanufacturers use various designs) diverts the piece of cut product suchthat the leading edge 13 of the piece 16 overlaps and lays down on thetail end of the previous cut piece. A weak point or disadvantage in thisover-shingling system is that the tail 19 of the previous cut piece ofmaterial must freefall and flatten itself on the slower moving belt 22so that the next cut piece 16 will be able to have its leading edgediverted by the diverter 18 and overlap the tail edge 19 of the previouscut piece. The speed that pieces can be cut and over-shingled is limitedby the time it takes for a tail of a piece to lie flat so that a nextcut piece can have its leading edge overlap the tail end of the previouscut piece. In the end, each piece 22 has a leading edge that overlapsthe previously cut piece and a tail end that is underneath the lattercut piece thereby forming a continuous stream of over-shingled pieces24. FIG. 2 shows a standard stream of over-shingled pieces 24 moving ina single direction on a conveyor 25.

A further disadvantage of over-shingling is if the conveyor or belt 20is moving too quickly, the leading edge 13 of one or more over-shingledpieces may become lifted and airborne. Thus, there are two factors inover-shingling that limit the speed of the overall movement of a streamof over-shingled pieces. It should be noted that the single stream ofover-shingled pieces 24 is moving at a rate on the belt 20 that isslower than the surface speed of the web 10.

It is further understood that it is presently standard in the industryto establish an over-shingled stream of pieces that are created via aweb that is cut by a cutter, and then accelerated by a gain device anddiverted into an over-shingled stream. Although various techniques canbe used to create the over-shingled stream, it is still understood thatthe overall speed of the product stream is limited by the prior arttechniques of over-shingling. In related industries for example, thenewspaper industry, the pages of a newspaper may be folded by varioustechniques but in the end the stream of completed newspapers are formedinto a continuous stream of over-shingled pieces prior to being stacked.Again, various techniques and methods are used, but in the industry, thestandard is a stream of over-shingled product.

Thus, FIG. 2 may be considered a figure of any printed product 22 thatis formed into an over-shingled stream 24 of folded or pieced product.The over-shingled stream is moving as a continuous stream on a conveyor25.

FIG. 3 depicts an over-shingling device similar to FIG. 1, wherein a web10 traveling at a first speed is cut at predetermined places by a cutter12 such that the leading edge of each cut piece 16 is grabbed by a gaindevice 14 that accelerates the cut piece 16 to a speed that is fasterthan the surface speed of the web 10. The cut piece 16 is then divertedand sent to a slower moving conveyor 20 wherein the cut piece's leadingedge 13 is laid on top of the trailing edge or tail of the relativepreviously cut piece thereby forming an over-shingled stream of product24.

Generally in the industry after an over-shingled stream of product 24has been created, it will move by conveyor systems 26 or by some othermeans through various processes to a location where it will usually bestacked by a stacking device 28. Stackers, like stacker 28, come in alarge variety of shapes, sizes and designs. Regardless of the widevariety of stacker designs, most stackers 28 follow a similar mechanismwherein shingled stream of pieces is turned upside down 30 so that eachpiece can be slid underneath the previously stacked piece in thestacker. In other words, the stackers 28 generally stack from the bottomof the stack rather than from the top. Stackers 28 may be in the form ofvertical or horizontal stackers, but again, tend always tend to turn theover-shingled stream of pieces 24 upside down such that the piece beingstacked slides underneath the previously stacked piece. As the piecesare stacked in the stacker 28, each piece 22 that is being stacked iscovered by the previous piece and is therefore no longer shingled butinstead, formed into a stack. These stacks now can then be removed andbundled by machine or manually. Stackers 28 are sometimes calledaccumulators which can be in either vertical or horizontalconfigurations.

It is understood that this prior art technique of creating anover-shingled stream and stacking the over-shingled stream into avertical or horizontal accumulator works well in the industry, but suchsystems have drawbacks. One of the drawbacks is related to adjusting theover-shingling device for various lengths or widths of pieces. That is,if a piece 16 is needed to be shorter than a piece that was run in aprior printing run, the adjustments for the over-shingling device can besignificant and time consuming in order to get a same or similar pieceoverlap in the over-shingled stream. The various speeds of theconveyors, wheels and pulleys of each device must be carefullyreadjusted. The distances between rollers and other mechanical devicesmust also be adjusted in order to handle different length pieces indifferent printing runs. Such a drawback can be very costly to themachine owner because the printing press is not running, but insteaddown and stopped for adjustments and reconfiguration for lengthy periodsof time between printing runs. In other words, “make ready time”, theamount of time it takes to make a machine ready for a new product run,is quite lengthy in the prior art type of over-shingling machines andsystems. Thus, such machines can be very costly during “make ready time”because the cost per hour can be from $600 to thousands of dollars perhour in downtime and profit lost while the printing system is made readyfor a run of pieces that are of a different size than a previous run.For example, if a greeting card manufacturer manufactures various sizegreeting cards on the same web printing press, each time a differentsize greeting card is created the cutting and shingling section of themachine requires significant adjustments and recalibration so that eachcut piece overlaps the previous cut piece in an over-shingled manner bya same amount in the continuous stream of over-shingled pieces. Thedowntime of a printing production or between printing productions isextremely costly to a printing company, therefore by shortening oreliminating this downtime would be greatly advantageous to a companythat prints and creates products from a moving web.

With respect to an over-shingled stream of pieces that are being stackedby a vertical stacker, which is the most used type of accumulator orstacker in the printing industry, there is a limit as to how high avertical stack can grow before it either falls over or the bottom piecethat is being inserted under the stack cannot be inserted into the stackdue to the overall weight of the accumulation of pieces above.Therefore, in various situations the faster the printing operation runsand the faster the stream of over-shingled pieces flow, then thefrequency that the accumulated stack of pieces needs to be removedincreases. Generally, manual labor is used to remove the accumulatedstacks from the machine so that the pieces can be placed in a box tiedwhen wrapped or put in the next stage of the packaging process offinished pieces. In some situations, when a line of over-shingled piecesis moving at maximum speed, the amount of labor required at the end ofthe line to remove accumulated stacks of pieces becomes overwhelming toa manufacturer in terms of the number of people required, the overallcost, and in various situations, the safety of having a large number ofpeople removing accumulated product from a same or similar accumulatorlocation. In fact, in certain circumstances a manufacturer will chooseto slow the printing line and manufacturing process down to a slowerspeed than its maximum in order to accommodate the manual laborobstacles at the end of the accumulator or line. For example, a companymay slow the line down so that two people can handle the workload at theaccumulator rather than hire an additional third person and run the lineat a higher speed. The bottom line, of course, is that it is costly toslow down a printing machine and manufacturing processes for a company.Thus, it would be advantageous to provide a system and method forcutting and producing a continuous flow of pieces that can beaccumulated in a manner that is more automated by machinery as well asable to operate at the machine's highest rate of speed for extendedperiods of time.

Furthermore, in the printing industry, it is fairly well establishedthat companies that make, manufacture and sell web cutters, such asrotary cutters, or devices that create over-shingled streams of piecesare different and unrelated companies from other companies thatspecialize in the manufacture and sale of accumulators and stackers,whether they be vertical or horizontally stacking. The machinerygenerally found in between the cutters/over-shingling devices and theaccumulator stackers may be various types of conveyors or systems 26 andfinishing systems that prepare the pieced material for stacking. It is arare and unusual situation wherein the same company manufactures both arotary cutter and over-shingling device as well as an accumulator orstacking device. As such, it has become standard in the industry to useover-shingling as the preferred technique of transporting cut piecesthrough various processes that exist between a cutter and over-shinglingdevice and the final stacking accumulator device.

What is needed is a new type of system or method of moving cut piecesfrom a web printing press at high rates of speed through a process andto an accumulator stacker that allows for the machinery to operate at ornear its maximum manufacturing rates. Furthermore, it would beadditionally useful if such machinery would be less costly and requirefewer weak points where pieces can jam, crumble, fold or clog themanufacturing process while it is operating at a full rate of speed.

SUMMARY

A new type of system and method for moving cut pieces from a webprinting press at high rates of speed through a process and to anaccumulator stacker is provided which allows machinery to operate at ornear maximum manufacturing rates. Embodiments of the invention includean under-shingling device which creates a stream of under-shingled cutpieces. Embodiments of the invention further may include a gapgeneration device for establishing a gap in the stream of under-shingledpieces at predetermined intervals.

In one embodiment, a method of processing cut pieces is provided. Themethod includes cutting a moving web of paper into a plurality of piecessuch that each piece has a same predetermined size or length. The web ofpaper is moving at a first speed. The method further includes grabbingeach cut piece and accelerating each cut piece to a second predeterminedspeed. The second predetermined speed if faster than the firstpredetermined speed. The accelerating of each piece establishes a firstgap between each one of the plurality of pieces that were cut from theweb. Each piece is then decelerated to a third speed while the tail endof each piece is lifted to allow the next piece to slide underneath andestablish an under-shingled stream of pieces.

Embodiments may further include accelerating a portion of theunder-shingled stream of pieces in order to generate a gap therein. Theaccelerating taking place at intervals such that the gap is generated atpredetermined intervals.

Additional embodiments may comprise a method of handling a flow ofproduct pieces that includes under-shingling each product piece undereach previous product piece to create a flow of under-shingled productpieces. The embodiment may further comprise generating a spacing gap atpredetermined intervals of the flow of under-shingled product piecessuch that a predetermined number of pieces are between each spacing gap.

Another embodiment provides a device for processing flat articles. Thedevice includes an under-shingling device. The under-shingling deviceincludes an accelerator section that accelerates each piece in a streamof pieces to a first speed, a decelerator decelerates each piece insuccession and a tail lifter that is underneath the stream of pieces andcontacts a tail portion of each article as it passes such that eachsucceeding articles' leading edge slides under the tail portion of thepreceding article. The tail lifter contacts each flat article as thedecelerator is decelerating the same article all the while thesucceeding piece is sliding thereunder.

A gap generation device may be provided downstream from theunder-shingling device. The gap generation machine has a first set ofpinch belts for moving a first portion of the under-shingled stream offlat articles at a first speed and a second set of pinch belts formoving a second portion of the under-shingled stream of flat articles ata second speed. The second speed being greater than the first speed suchthat the second set of pinch belts when operating during a predeterminedinterval create a gap in the stream of under-shingled flat articles.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding, reference is now made to thefollowing description taken in conjunction with the accompanyingDrawings in which:

FIG. 1 illustrates a prior art side elevation of a cutter andover-shingling apparatus;

FIG. 2 illustrates a side elevation of an over-shingled stream ofpieces;

FIG. 3 illustrates a prior art side elevation of a cutter,over-shingling device, conveyor system and drum stacker system;

FIG. 4 illustrates a side view of spaced, cut pieces;

FIG. 5 illustrates a side elevation of an exemplary cutter andunder-shingling apparatus with a tail grabber;

FIG. 6 illustrates an exemplary side elevation of a gap generatingdevice and method; and

FIG. 7 illustrates an exemplary side elevation depicting an exemplarystream of under-shingled pieces having a gap every predetermined numberof under-shingled pieces and an associated stacker-accumulatormechanism.

DETAILED DESCRIPTION

Referring now to the drawings, wherein like reference numbers are usedherein to designate like elements throughout, the various views andembodiments of an under-shingled article handling and stacking systemand method are illustrated and described, and other possible embodimentsare described. The figures are not necessarily drawn to scale, and insome instances the drawings have been exaggerated and/or simplified inplaces for illustrative purposes only. One of ordinary skill in the artwill appreciate the many possible applications and variations based onthe following examples of possible embodiments.

Referring to FIG. 1, it is shown that a web 10 is cut by a cutter orrotary cutting machine 12 at predetermined lengths. It is important tounderstand that the leading edge 17 of the piece being cut must begrabbed by the gain or accelerator device 14 prior to the cut or elsethe cut piece will fall to the ground and not be transferred through thesystem. The about to be cut piece of paper's leading edge 17 is grabbedby the accelerator 14 so that it can be placed on a predetermined paththrough the processes. The grabbing device or accelerator 14 pulls thejust cut piece away from the cutter such that a small space 15 isestablished between each of the consecutive pieces as they are cut andthen accelerated by the gain accelerator 14. In all known currentdesigns this acceleration and resulting over-shingled stream isperformed at a fixed speed. In other words, the manufacturer decidesthat the accelerator should accelerate each piece to a fixed speed thatis a certain percentage greater than the speed of the web 10. Thispercentage is called the gain of the accelerator 14. Thus, the cut piece16 is removed from the web 10 at a faster rate of speed than the webspeed wherein the percent increase of the speed is referred to as thegain. The change in speed creates a small distance or space or gap 15between each consecutive piece as they are cut. The space or gapestablished by the accelerator 14 between each consecutive piece 16 mustbe large enough to be sufficient for under-shingling wherein the paperis allowed to free fall via a diverter such that there is enough timefor the next piece to overlap the tail of the previously cut piece on aslower conveyor 20. The slower conveyor may be moving at a rate that isslower than the speed of the web 10.

In an embodiment of the invention, an accelerator and under-shingler isprovided that has an adjustable speed or gain such that the cut piece isnot necessarily moved at a constant speed during the acceleration andunder-shingling process. An embodiment is adjustable in such a way thatthe space between the consecutive pieces is sufficient forunder-shingling interpretation (the mechanical aspect of the newunder-shingling concept) and/or the tail grabbing operation of theexemplary embodiments which will be discussed below.

Referring now to FIG. 4, an example is provided to aid the reader inunderstanding some concepts associated with embodiments of theinvention. Assume a web is running at 1,200 feet/minute, which in thisexample is equal to 35,000 impressions/hour (IPH). The 35,000impressions/hour is indicative of how many times the printing cylinderrotates in order to produce identical impressions on the web as the webmoves. Each time the image is printed by the press' print cylinder onthe web it is called a single impression. A single impression mayinclude, for example, four copies of a same printed material. In anexemplary example, assume that the impression is twenty-four inches longand has four copies therein. The impression is cut by the rotary cutter12 into four six inch pieces such that each piece or product 16 is onequarter of one impression 40. If the accelerator 14 accelerates eachpiece so that a one inch space is created in between each consecutivepiece, then the accelerator must operate at a gain of about 0.166%. Thismeans that the accelerator must accelerate each piece such that it istraveling about 0.166% faster than the surface speed of the web 10 priorto the cutter 12. The one inch space 42 generated by the accelerator 14,in this example, provides enough space for the over-shingling of a priorart device. FIG. 4 depicts an example spacing of cut pieces as they exita prior art accelerator and over-shingling device operating at a fixedspeed.

Referring now to FIG. 5, the importance of the example in FIG. 4 isprovided because the accelerator section 50 of an exemplary embodimentis now being used in conjunction with the under-shingling device 51 tocreate a slow down in the progression of cut pieces such that a newlycut piece 52 slides under the tail end of the just previously cut piece54. This under-lapping or under-shingling is performed without allowingany pieces to freely move or free float in the air as is used andrequired in prior art devices in the diverter section 18 of a prior artover-shingling device. Furthermore, embodiments of the invention do notallow the product to fly in or through air creating an uncertainty inthe overall performance of the device. Embodiments of the presentinvention fully control each sheet or cut piece as it is cut,accelerated, under-shingled and decelerated through embodiments of thenew novel under-shingling process. When a prior art diverter 18 (fromFIG. 1) has a jam in it due to an inaccurate cut or crease, crinkle orotherwise, the entire machine comes to a screeching halt due to freeflying product sheets through the diverter being a weak point in theprior art manufacturing process. Hundreds of thousands of pages may becut and destroyed in a prior art over-shingling process before the lineis shut down.

Embodiments of the present invention avoid this weakness or flaw in theprior art over-shingling process by establishing a more controlledunder-shingling process, method and device that can operate at higherspeeds with more accurate over or under-shingling for substantially anysize piece in different printing runs.

In embodiments of the present invention, the acceleration or take awayspeed of the accelerator 50 is managed and controlled with an adjustablegain to increase product velocity depending on the product length andthe speed of the web. By adjusting the gain of the exemplary acceleratorthe space or gap created between each piece can be controlled to be thesame size regardless of the size of the cut piece. Using the example ofFIG. 4, regardless of the size of the piece 16 (i.e., 5″, 6″, 8″, 24″)the gap size 42 can be kept constant at, for example one inch. It isunderstood that the gap size can be adjusted to be any size that themanufacturer requires. The point here is that the gap size can becontrolled to be consistently the same size regardless of the cut piecesize and regardless of how fast the surface speed of the web is running.The overall goal is to create a constant distance relationship betweeneach product regardless of the length of the product or the speed atwhich the product is being printed and cut from the web printing device.It is important to understand that exemplary embodiments may have aspace 42 between each product of substantially any workable distance,but the space can be controlled to be the same distance regardless ofthe speed of the web or the product length. It should further beunderstood that the gap size 42 can be selected to accommodate downstream devices. That gap size is elected to establish a fixedunder-shingling distance, so that every piece regardless of length orspeed of the overall stream of piece movement is under-lapped by thesame distance or amount.

Still referring to FIG. 5, we see a web 10 approaching a rotary cutter12. Again it is understood that there are varying types of rotarycutters in the industry and that embodiments of the invention are notlimited to a rotary cutter, but could use substantially any type ofappropriate cutter. The web 10 is grabbed by the adjustable accelerator50 and sliced to its predetermined length. The newly cut piece 52 isaccelerated forward by the adjustable accelerator 50 via the drivenrollers 56. Each of the driven rollers 56 are driven at the same speedthereby accelerating the cut piece 52 forward. The next portion of anembodiment, sometimes referred to as a tail grabber, lifts the tail 77of the previously cut piece 54 up via a vacuum roller 58 whose lowestouter circumferential surface is positioned from about 1 mm to 2 cmhigher than the upper surface of the newly cut piece 52 or above theguide surface 57 below the stream of newly cut pieces. The vacuum roller58 lifts or holds the tail portion 75 of the previously cut piece 54(grabs the tail end) such that the newly cut piece 52 is accelerated bythe accelerator 50 and the associated drive rollers 56 to slideunderneath the tail portion of the previous cut piece 54. A positioneror end lifter 60, which has a surface speed that is substantiallysimilar to the surface speed of the vacuum roller 58 has spaced flaps,rods or bumps extending outward thereon (enforcers 62) that slow andhelp position the newly under-shingled piece 52 as it slides underneaththe previously cut piece 54. The circumferential surface speed of thevacuum roller 58 and the positioner with the enforcers 62 thereon aresubstantially similar. Furthermore, the circumferential speed of rollers56 in the adjustable accelerator is 20%-50% faster than thecircumferential speed of the vacuum roller 58 and the enforcers 62.Roller 64 may be an idler roller, which may be spring loaded to float upand down above each piece in the direction of the arrows 66. Driveroller 68 may operate at substantially the same speed as drive rollers56, but it may be necessary that drive roller 68 operate at a speed suchthat its circumferential surface is moving at a speed that is betweenbeing less than or equal to the speed of drive rollers 56 and greaterthan or equal to the speed of the circumferential speed of vacuum roller58. It is understood that during startup, idler roller B may have to beaccelerated to at least a predetermined speed that is substantiallysimilar to the speed of roller 68 so that product flow through theexemplary tail grabber and under-shingling device does not jam, crinkleor rip pieces as they flow therethrough. Pinch rollers 71 and 72 arerotating with a circumferential speed that is substantially the same andsubstantially as the circumferential speed of vacuum roller 58 and theenforcers 62. As such, each piece is accelerated and decelerated in acontrolled manner through the accelerator 50 and under-shingling 51devices.

In some embodiments of the invention, the distance 76 between the pinchroller 71 and the vacuum roller 58 is equal to the length of a piece(54, or 52) minus the under-lap distance 78. The under-lap distancebeing the distance that the leading edge 74 of a just cut piece 52under-laps the tail end 75 of a previously cut piece 54. The under-lapdistance can range from about one quarter of an inch to more than halfthe length of a piece 52. The length of the piece 52 is equal to thedistance from the leading edge of the piece 74 to the trailing edge ortail 75 of the piece.

In another embodiment of the invention, roller 64 and roller 68 are bothidle rollers that may speed up and slow down with the speed of the pieceor product moving therebetween. In yet another embodiment, the same tworollers 64 and 68 may be pinch rollers that spin at substantially thesame speed as each other, but may vary with the idle or with the speedof the product or piece 54 moving therebetween as well. Furthermore,both rollers 64 and 68 may move up and down in a substantially verticaldirection to aid the lifting or holding of the tail end of thepreviously cut piece 54 by the vacuum roller 58. The up and downmovement of pinch rollers 64 and 68 may be described as an up and downoscillation having a frequency equal to the piece frequency movingtherebetween. The oscillation may have an upper peak position thatoccurs sometime during the middle 80% of the length of a piece 54. Amiddle 80% length of a piece is shown in FIG. 4 as the central area 80of a piece 55 that is between the leading edge 74 and the trailing edge77 of a piece 55. The possible oscillation of roller 68 is shown withthe dotted arrow 82 in FIG. 5.

As can be seen, an exemplary embodiment receives newly cut pieces 52from a web 10 and rotary cutter 12 and proceeds to tail grab apreviously cut piece 54 by various means and hold the trailing portionor tail 75 of a previous cut piece in an uplifted or at an elevatedlevel such that a newly cut piece 52 can be inserted, at leastpartially, thereunder resulting in the continuous production of anunder-shingled stream of pieces 86. The under-shingled stream of pieceshas the advantage of being able to be created and to move at a rapidrate along a production line and conveyors 88 without being lifted orblown by air or being caught under a leading edge of the piece asdiscussed above with respect to over-shingled streams of product 24 inFIG. 2. Furthermore, embodiments of the invention provide a tailgrabbing, tail holding or tail lifting means that is not limited inspeed or movement by a free falling portion of a cut piece as discussedabove with respect to the diverter sections of an over-shingling device.This advantage allows an under-shingling device in accordance with thevarious embodiments to operate at higher web speeds and higherproduction speeds thereby increasing production of finished product inless time than previous devices.

In other embodiments of the invention, the end lifter 60 may rotate suchthat the enforcers 62 are used to slow down the accelerated and nowdecelerating newly cut piece 52 as it slips underneath the tail portion75 of the previously cut piece 54. The enforcers 62 may also, as theymove, lift the tail portion 75 or a portion proximate to the tail end 77of the previously cut piece 54 from one sixteenth of an inch to about ahalf an inch to aid in the piece's continued contact with or hold of thevacuum roller 58.

In yet another embodiment of the invention, the roller 68 may not be aroller at all, but instead, be a smooth element that is substantiallyarced such that its upper surface is adjacent to the bottom of thepreviously cut piece 54. As the previously cut piece 54 slides over thearced smooth surface 68, the piece 54 is nudged upward. Furthermore, thesmooth surface of the arc 68 may oscillate up and down to guide thepiece there above it slightly upwards and aid with the under-lappingprocess. In yet another embodiment of the invention, the combination ofpinch rollers 64 and 68 may be a guide that moves up and down therebyaiding with lifting the previously cut piece 54 to maintain the trailingportion of the previously cut piece in contact with the vacuum roller 58while the next piece slides thereunder.

Referring now to FIG. 6, a gap generator associated with the stream ofunder-shingled pieces or product is described. This gap generator 90creates a gap in the now formed under-shingled stream of product 86 asit moves along the conveyor system (not specifically shown). Anexemplary gap generator is used to create a gap in the stream ofunder-shingled pieces every predetermined number of under-shingledpieces. That is, a gap is created in the stream 84, for example, everytwenty pieces. FIG. 6, for simplicity shows a gap generator that createsa gap in the moving stream of product 86 every four under-shingledpieces. The gap 92 is shown as it is being created and after it is beingcreated 92 and 92′.

A first set of pinch belts 94 and 96 pinch the stream of under-shingledproduct 86 such that each individual product or piece is held in placerelative to the other individual products or pieces as they moves as astream between the pinch belts 94 and 96. The under-shingled product istransferred from the first set of pinch belts 94, 96 to a second set ofpinch belts 98 and 100, which for a predetermined amount of time operatesuch that the belts 98, 100 move at substantially the same speed as thebelts 94 and 96. In this example, four pieces of product are heldbetween pinch belts 98 and 100, the speed of the pinch belts 98 and 100simultaneously increase or accelerate to a faster speed thereby creatinga gap between the last piece 102 in the pinch roller combination 98, 100and the leading piece 104 in the pinch roller combination 94, 96. Byaccelerating the product in the second set of pinch belts 98, 100 a gap92 is established. The second set of pinch belts 98, 100 are thendecelerated back to the same speed as the first set of pinch belts 94,96 and the process repeats every predetermined number of pieces. In someembodiments, the first and second sets of pinch belts are interspersedbetween each other such that while the first set of pinch belts ispinching the stream section and moving the stream at a first speed, thesecond set of pinch belts is not adjusting the speed of the streamsection. Conversely, while the second set of pinch belts are pinchingthe stream section and moving the stream at a second speed, the firstset of pinch belts is not adjusting the speed of the stream section.Other techniques for establishing a gap in a moving stream ofover-shingled pieces have been established and are known in the art, forexample, U.S. Pat. No. 4,161,092 to Buday et al. at column 12 beginningat line 58 through column 14, line 19, teaches another technique ofproviding a gap and is hereby incorporated by reference. Thus, variousmeans for gap creation are known in the art of over-shingling productstreams. Such processes may also be used in under-shingled streams.

Referring now to FIG. 7, a stream of under-shingled pieces is shownhaving a gap 92 created by a gap generation device or means everypredetermined number of pieces. The predetermined number of piecesbetween each gap 92 may be a few pieces to hundreds of pieces. Thenumber of pieces in between the gap represents a number of pieces thatthe manufacturer would like in a stack of pieces. The predeterminednumber of pieces 112 can be provided to a stacking device merely byplacing an obstruction or vertical stacker 114 in the way of the movingpredetermined number of pieces between a gap. The pieces will stackautomatically as each piece in the over-shingled stream slidesunderneath the piece in front of it thereby creating a stack of piecesequal to the number of predetermined pieces between each gap.

During the gap period 92 a full stacker 114 may be moved out of the pathof the stream of over-shingled pieces while another stacking device 115or obstacle is placed in front of the stream of over-shingled pieces toaccumulate the next predetermined number of pieces up until the next gap92. The result is a plurality of stacks comprising a predeterminednumber of pieces as predetermined by the manufacturers' spacing and gapcreation in the over-shingled product stream. This method ofaccumulating or stacking pieces eliminates the need for turning anover-shingled stream of product (i.e., from the prior art) upside down,as shown in FIG. 3, via a drum or other means so that the accumulatorwill function such that stacking proceeds with each piece being slidunderneath the preceding piece in the accumulator. The combination ofthe gap and the accumulators eliminates the need for having additionalpersonnel continuously having to watch the end of the line at theaccumulation section and remove stacks of product from the accumulatorprior to it overfilling or overflowing. In an exemplary embodiment eachaccumulator 114 is stacked with a pre-counted or predetermined number ofproduct pieces from the under-shingled stream. The gap 92 provides timefor a first accumulator 114, after being filled with a firstpredetermined number of pieces, to be moved out of the way or indexedsuch that a second accumulator 115 can be put into position toaccumulate the next predetermined number of product or pieces 112. Whenthe next gap arrives at the accumulator, the accumulator 115 is movedout of the way and a new accumulator is then placed in front of thestream of under-shingled pieces and the next predetermined number ofpieces are accumulated in the accumulator. In some embodiments, the gapis needed for providing a space or short time period for an obstacle tobe placed in the stream such that a means for producing an accumulatedstack of product can be created and then pushed as a stack out of thestream flow. The resulting accumulated stack will have a predeterminedcount equal to the number of pieces between the gaps of predeterminednumber of pieces and may provide a means for simplifying boxing,wrapping, banding or finalizing the finished stack of pieces forcomplete production and delivery.

As is probably noticed by one reading this document, an advantage ofunder-shingling is that an under-shingled stream allows one to put theirhand or an object in front of a leading edge of the under-shingledstream and as a result, one will find that each subsequent piece willslide underneath the piece in front of it and a stack will beaccumulated right into the person's hand or in front of the obstacleplaced in front of the stream of under-shingled pieces. Thus, theaddition of another machine, for example, a prior art style stacker,which requires that the over-shingled stream be turned upside down priorto being stacked can be eliminated. Thus, embodiments of the presentinvention remove some complexity of prior art stacking devices thatincorporate, for example, a drum or other means for turning theover-shingled stream of pieces upside down prior to being stacked.

Referring back to the gap generator, the gap generator of an exemplaryembodiment or method grabs a predetermined number of under-shingledpieces, for example one-hundred, and accelerates them slightly fasterthan the continuous stream of under-shingled pieces, but the relativeposition of each piece in the accelerated predetermined number of piecesremains constant with respect to each other piece therein. Thus, theamount of under-shingling or overlap between each piece remains constanteven though a gap is being created in the continuous stream ofunder-shingled product.

Advantages of embodiments of the present invention and method provide ameans for increasing the speed of processing of pieces in a printingsystem whereby the pieces can be moved as a continuous stream ofunder-shingled pieces at a higher rate of speed than previously possiblein over-shingled techniques. Additionally, by establishing a gap atpredetermined places in the under-shingled stream of pieces, apredetermined count of pieces can be accumulated and indexed at or nearthe end of the stream in a manner such that the human or worker is notrequired to be present the entire time. Furthermore, predeterminedstacks of pieces are generated in a manner such that each stack can havea specific count for boxing, wrapping or placing in a finished productcontainer. Finally, embodiments of the present invention removeadditional conveyor equipment that was previously required between arotary cutter and a stacking mechanism wherein many adjustments wererequired when runs of pieces having different sizes were initiated. Inother words, the downtime, or setup time for different runs of differentsized products or pieces is greatly shortened because the number ofmechanical adjustments and tuning in embodiments incorporating thepresent invention are minimized when compared to previous devices usedin similar areas of a printing, cutting and accumulating process.

It will be appreciated by those skilled in the art having the benefit ofthis disclosure that this under-shingled article handling and stackingsystem and method provides a improved technique for handling flatarticles such as paper at increased rates of speed while taking up lessfactory space. It should be understood that the drawings and detaileddescription herein are to be regarded in an illustrative rather than arestrictive manner, and are not intended to be limiting to theparticular forms and examples disclosed. On the contrary, included areany further modifications, changes, rearrangements, substitutions,alternatives, design choices, and embodiments apparent to those ofordinary skill in the art, without departing from the spirit and scopehereof, as defined by the following claims. Thus, it is intended thatthe following claims be interpreted to embrace all such furthermodifications, changes, rearrangements, substitutions, alternatives,design choices, and embodiments.

What is claimed is:
 1. A device for processing flat articles, the devicecomprising: an under-shingling device; and a gap generation device forgenerating a gap at varying intervals of the under-shingled steam offlat articles, the gap generation device comprising: a first set ofpinch belts for moving the a first portion of the under-shingled streamof flat articles at a first speed; and a second set of pinch belts formoving a second portion of the under-shingled stream of flat articles ata second speed during predetermined intervals, the second speed beinggreater than the first speed.
 2. The device of claim 1, wherein thevarying intervals range from about 4 to hundreds of flat articles in theunder-shingled stream of flat articles.
 3. The device of claim 1,wherein when the first portion and the second portion are a same portionof the under-shingled stream of flat articles, and wherein when thefirst set of pinch belts are moving the same portion, the second set ofpinch belts are not moving the same portion, and wherein when the secondset of pinch belts are moving the same portion, the first set of pinchbelts are not moving the same portion.
 4. The device of claim 1, whereinthe smallest interval of the varying range of intervals is dependent ona number of flat articles comprised in the first portion of theunder-shingled stream of articles.
 5. The device of claim 1, wherein thesmallest interval of the varying range of intervals is dependent on anumber of flat articles comprised in the second portion of theunder-shingled stream of articles.
 6. A method of processing asubstantially flat article comprising: creating an under-shingled streamof flat articles; creating gaps at varied determined intervals of theunder-shingled stream of flat articles, the gaps comprising a first gapand a second gap; placing a first obstacle in the first gap and in frontof the under-shingled stream of flat articles; accumulating theunder-shingled stream of flat articles into a first bottom fed,vertically created stack of flat articles; removing the first obstacleat the second gap; placing a second obstacle in the second gap and infront of the under-shingled stream of flat articles; and accumulatingthe under-shingled stream of flat articles into a second bottom fed,vertically created stack of flat articles.
 7. The method of claim 6,wherein the step of creating an under-shingled stream of flat articlescomprises: providing a plurality of substantially flat articles, eacharticle having a same predetermined length; grabbing and acceleratingeach article to a second predetermined speed, the second predeterminedspeed being faster than the first predetermined speed, the acceleratingcreating a first spacing between each article; decelerating each articleto a third predetermined speed while lifting a tail end of each articleusing a means for tail lifting to allow a next article to slide thereunder to create the under-shingled stream of substantially flatarticles, the next article being the article immediately following eacharticle, each next article under-shingling each article by apredetermined amount.
 8. The method of claim 6, wherein the step ofcreating gaps at varied determined intervals comprises: accelerating aportion of the under-shingled stream of substantially flat articles andcreating the first gap between a first portion and a second portion ofthe under-shingled stream of substantially flat articles; acceleratinganother portion of the under-shingled stream of substantially flatarticles and creating the second gap between the second portion and athird portion of the under-shingled stream of substantially flatarticles.
 9. The method of claim 6, wherein the step of creating gaps atvaried determined intervals comprises: decelerating a portion of theunder-shingled stream of substantially flat articles and creating thefirst gap between a first portion and a second portion of theunder-shingled stream of substantially flat articles; deceleratinganother portion of the under-shingled stream of substantially flatarticles and creating the second gap between the second portion and athird portion of the under-shingled stream of substantially flatarticles.
 10. The method of claim 8, wherein creating the first gapbetween the first portion and the second portion of the under-shingledstream of flat articles includes increasing an amount of overlap of atleast one flat article with respect to another adjacent flat article inthe portion of the under-shingled stream of substantially flat articles.